Deadbolt locks for doors have been in use for a considerable length of time, but they generally require a key to both open and close. Prior art examples of locks not requiring a key are as follows:
U.S. Pat. No. 1,736,761, to Hoffner, discloses a door with a plurality of locks that are opened simultaneously by a push button solenoid arrangement.
U.S. Pat. No. 3,242,708, to Sanchez, discloses a rather complex system of remote control keyless automatic electronic locks, wherein a particular, but changeable combination of pushbutton operations are required to open the door on which this system is installed.
U.S. Pat. No. 4,434,635, to Borgato, discloses a manual and electrically operable automatic hook lock for sliding gate applications.
U.S. Pat. No. 4,557,121, to Charlton, discloses an electrically operated bolt lock that may be spring loaded into either an open or closed position, and may be solenoid operated to the other position.